The relationship of N-glycosylation and porcine duodenal morphology and function.

Intestinal epithelial cells are the primary performers of intestinal functions and have a highly glycosylated surface. Membrane proteins are regulated by N-linked glycosylation, making it likely that glycosylation plays a key role in cell differentiation. To investigate the effect of glycosylation on intestinal morphology, we selected 90 pigs with an average initial body weight of 27.74 ± 0.28 kg to be housed for an experimental period of 100 d. Individuals with different villus heights were screened on the basis of duodenal intestinal morphometrics data and demonstrated that the apparent digestibility of amino acids in ileo-terminal chyme was positively correlated with villus height. The regulatory mechanism of intestinal villus height was then analyzed by transcriptomic sequencing and glycosylation proteomics, and it was found that this difference might be caused by the N-glycan biosynthesis pathway and different N-glycosylation processes on the cell surface. mRNA of genes related to the N-glycosylation synthesis pathway were more highly expressed in individuals with high villus height (P < 0.05), and the expression of genes targeting the Wnt signaling pathway was consistent with the trend of glycosylation-related genes, and the expression of its repressors was lower (P < 0.05). In order to verify the above results, 24 weaned piglets ((6.58 ± 0.15 kg) at 21 d of age) were randomly divided into 3 groups fed 0, 1, 3 g/kg N-acetyl-D-glucose, and 24 weaned piglets ((4.27 ± 0.13 kg) at 21 d of age) were randomly divided into 3 groups fed 0, 0.5, 1 g/kg fucose, then the samples were taken for testing after 28 d. The results showed that glycosylation processes occurring on the surface of duodenal intestinal epithelial cells can influence intestinal morphology through the Wnt signaling pathway.